Improvement in hot-air drums and grates for stoves and furnaces



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. B. F. CAMPBELL. Hot-Air- Drum and Grate for Stoves and Furnaces.

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B. F. CAMPBELL.

HotAr Drum and Grae for Soves and Furnaces. 510.128,70?. Patentedluly 9,1872.

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BENJAMIN F. CAMPBELL, OF BOSTON, MASSACHUSETTS.

IMPROVEMENT IN HOT-AIR DRUMS AND GRATES FOR STOVES AND FURNACES.

Specilication forming part of Letters Patent No. 128,706, dated July 9, 1872.

To all whom 'it may concern:

Be it known that I, BENJAMIN F. CAMP- BELL, of the city of Boston and State of Massachusetts, have invented certain new and useful Improvements in Furnaces and Stoves for Heating Air 5 and do hereby declare the following specification to be a true and exact description of the same, reference being had to the accompanying drawing, in which- Figure 1 is a vertical cross-section through the line a a of Fig. 3. Fig. 2 is a View of the the rings or bands which operate on the exterior surface of the air-lines or passages. Fig. 3 is a vertical cross-section through the line b b of Fig. 1 and Fig. 4 is a horizontal section through the line c cof Fig. 1.

My improvements relate, first, to an im proved arrangement of hot-air iiues or passages, by means of which the air to be heated can be taken in from either or bo'th sides of the furnace and through such ues up over the fuel-chamber to opposite sides, and forming the upper surface thereof 5 or each set of flues or passages may terminate after passing above the fuel-chamber on its own side. In either case this system of ilues will admit of the hot-air chamber, into which they all lead, being divided from front to rear so as to give each half of the house its proper share of the heat. This arrangement of the flues brings within a small space a large amount of radiating surface-from three to four times as much as by any other known plan; and the air enters in much larger quantities, and passes more freely over such surfaces, thereby obtaining an amount of heated air uncontaminated by coming and remaining in contact with overheated iron; second, in providing thesefflues or passages with rings or bands of stout wire or strips of metal,which encircle their exterior surface so as to remove any deposit or coating of soot or ashes therefrom, and thus at all times to have them present a metallic surface to the products of combustion arising from the firechamber, and wholly free from any intervening non-conducting substance; third, in an improved construction of fire-grate, whereby the grate may be more easily shaken of its ashes, or removed or inserted in place, as occasion may require, and consists of placing the axis of the grate in a frame, and resting such frame on friction-rolls, as hereinafter described.

In the drawing which serves to illustrate my improvements there is shown a furnace in a portable form. The exterior dotted lines are intended to represent the exterior casing, or,

if a stationary house-furnace, the walls or masonry work.

c a, te., are fines or passages for air, which extend from each side of the furnace above the fire-pot b, up over the fuel-chamber, to the opposite side from which they entered, passing each other alternately in a diagonal direction through the space above the fuel# chamber. They may, instead of crossing over to opposite sides, turn up at or near the middle ofthe said space and terminate on the saine1 side lor half-portion of the furnace at which they entered. Such ilues may so pass up or across at any desired angle, from one only or both sides, terminating at any convenient point, so long as they incline from the sides toward, and pass over on an angle above the iirepot or fuel-chamber. By this construction the area of heated surface with which the air is brought in contact is largely increased, according to a given space. The fines being so arranged directly over the fire-pot they receive the greatest amount of heat and admit of the passing through of the largest possible body of air for such space, such air being warmed in so passing through without being too long in contact with the heated surface. The air so warmed will be as healthful as if generated by steam or hot water, and the ventilation good.

In the case of the use of my apparatus as a stove, the exterior casing c (shown by dotted lines) is dispensed with, and the cold air enters at the lower sides and passes 0E at the top without obstruction. In the portable furnace, also in furnaces built around with brick or other suitable material, there are air-chambers d and e, both below and above, and the air is taken out of the upper air-chamber e e through one or more of the openings ff, 85e., the chamber being divided by a ridge or partition at g, so as to admit of each side of the house being equally supplied with theheat. On the exterior of each of these flues or passages for air are placed rings or bands of metal, h h,

attached owner by a rod or stout wire, the distance between of about half the length of the surface required to be passed over. Each rod extends through the side of the furnace or stove at i i, &c., and is operated by being pushed back and forth, which carries the rings over the exterior surfaces of the flues. These surfaces, exposed to the action of the heat and flame of the combustion-chamber, become coated with dust and ashes, and unless frequently scraped, much' heat is lost by reason of thc non-conducting properties of such deposit.

j is the grate7 hung by a center-bar having its bearings in a frame, 7c. Beneath the firepot are inserted two friction-rolls, l Z, which have their bearings in ledges m m. The frame 7c containing the grate rests upon and can be moved back and forth over these rolls, thereby diminishing friction in the shaking of the grate. On one side of the opening at which the grate is inserted in the furnace or stove is placed a projecting arm, u, With the end bent over at a right angle. 0n the front end of the grate-frame is placed a projecting arm, o, to the end of which is hinged a cross-rod, p, having an eye at one end and a handle at the other. In the operation of the shaking of the grate this eye is passed over the bent end of the arm n, and by the handle a rapid motion can be given to the frame containing the gratesulrlface, in order to free such grate from its as es.

This construction enables the grate to be Claims.

l. The arrangement of hot-air lues passing at any angle above the tire-pot, and forming the upper surface thereof, and passing out at the side or top of the furnace or stove, substantially as and for the purposes described.

2. The arrangement, upon the exterior surface of the hot-air lines or passages, of rings or bands, substantially as and for the purposes described.

. 3. The arrangement of the grate-frame on friction-rolls, substantially as and for the purpose described.

4. The combination of the projecting arm of the grate-frame and its crossrod p, containing an eye at one end, with the angled end of the arm n, substantially as and for the purposes described.

B. F. CAMPBELL.

Witnesses CHARLES WHITTIER, HENRY C. CAMPBELL. 

